Queensland and Western Australia will not follow the two biggest states into a $3.8 billion national redress scheme for child sexual abuse victims unless critical issues are resolved.

The agreement with NSW and Victoria means more than half of the estimated 60,000 eligible survivors nationwide will be covered by the federal government's scheme, provided churches and charities in those states also sign up.

Prime Minister Malcolm Turnbull hailed it a historic day and urged other states and non-government institutions to sign on or be judged very harshly.

"If a church or a charity or institution doesn't sign up, I hope they will be shamed and we will be using the megaphones we have to encourage them to sign up," he said on Friday.

"If they don't they will fail the test of justice and they will fail the people they seek to represent."

Queensland and WA say they cannot sign on because the federal government has failed to provide crucial information about the scheme, which begins on July 1.

"We are disappointed that the Commonwealth is dragging its feet on this issue," a WA government spokesperson said.

A Queensland government spokesman said it was disappointing there were still so many unresolved critical issues, including eligibility criteria and ensuring key elements cannot be changed unilaterally without agreement of participating states and territories.

"Without these details it would be irresponsible for the government to decide whether to opt in to the scheme," he said.

South Australian Premier Jay Weatherill acknowledged issues remained but was confident an agreement would be reached.

SA agreed in-principle to sign on during its election campaign, backing away from its firm opposition.

Mr Turnbull, NSW Premier Gladys Berejiklian, Victorian Premier Daniel Andrews, victims' advocates and the Catholic Church urged other states and all institutions to sign up.

"There are no more excuses for any church, any charity or frankly any other government in this nation to not sign on to this proper, fair and balanced national redress scheme," Mr Andrews said.

Australia's Catholic leaders have said they will join the scheme, with the church estimating it will be liable for about $1 billion in compensation.

The church's Truth Justice and Healing Council CEO Francis Sullivan expected Catholic entities in NSW and Victoria would now sign on, but cautioned that getting the two biggest states on board was only "halfway there".

He called for detailed information including the new federal and state legislation required to make the Commonwealth scheme a national one.

Despite widespread criticism, the $150,000 maximum compensation payment under the national scheme will not be raised to the $200,000 cap recommended by the child abuse royal commission.

Sex offenders or anyone jailed for five years or more for serious crimes also remain blocked from redress under the scheme.

Mr Turnbull defended the $150,000 cap and criminal exclusion, saying they were necessary to maximise participation in the scheme.

He will deliver a national apology to survivors at the end of the year.